Contamination of the environment with waste products and other impurities is called
Pollution. Substances whose presence in air, water or soil is harmful to human
beings, animals and plants are called pollutants.
Types of Pollution: -
¾ Air Pollution
¾ Water & Soil Pollution
¾ Sea Pollution
¾ Radiation
¾ Noise
1-Air Pollution: -
Air Pollution is mainly caused by dust, sulfur dioxide, carbon dioxide, carbon
monoxide, nitrogen oxides, hydrocarbons and ozone.
Sources: -
i) Fuel gases from garbage burning.
ii) Exhaust gases from fossil fuels burning in industries and auto motives.
2-Water & Soil Pollution: -
This includes untreated sewage, pesticides and fertilizers, inorganic compounds,
waste from radioactive metals, heavy metals like mercury, cadmium, arsenic etc.
Sources: -
i) Municipal wastes
ii) Industrial wastes
iii) Agricultural wastes.
Effects of Pollutants on Environment: -
i) Sulfur dioxide damages leaves of plants. It corrodes metallic and stone
structures.
ii) Higher concentrations of carbon dioxide are harmful to animals.
iii) Carbon monoxide combines with hemoglobin to reduce oxygen in blood.
iv) Oxides of nitrogen corrode metals and stones. They produce photochemical
smog that inhibits the plants growth.
v) Higher concentrations of ozone reduce air visibility and cause health problems
e.g. eyes irritation and headache.
vi) Untreated sewage is source of germs causing cholera and typhoid
vii) Densely populated bacteria consume the oxygen of water, effecting the water
animals and even death of fishes.